Insulation provides warmth by entrapping air. Natural insulators, such as wool or feathers, and synthetic insulators made of polymer fibers are well known. Insulated fabrics are used for protection against cold and sometimes for protection against other outdoor elements such as wind, rain, sleet and snow. For example, insulated fabrics are found in outdoor apparel, blankets, and window liners. Insulated fabrics are not, however, found in cold-weather shelters.
Traditional cold-weather shelters, such as ice fishing huts and winter tents, are made out of non-insulated canvas. Cloth shelters fail to provide sufficient warmth or ventilation because they “sweat or frost up” from moisture and melting ice. Cold exterior temperatures abut heat and moisture from the interior of the shelter causing interior condensation problems. Health issues, such as nausea and sickness from prolonged exposure to heating sources, are known to plague ice fishermen that dwell for long hours in traditional canvas shelters. Furthermore, cloth shelters are costly both financially and environmentally because they lack sufficient thermal resistance.